Disclaimer: All things "Castle" belong to ABC.

Author's Note: Because I wanted to see more of how Alexis would deal with Castle's disappearance. And because "Castle" has eaten my brain this week. Warning: Spoilers ahead!

Promises

Kate quietly took out her keys and unlocked the door of the loft, using all the stealth she was capable of since it was past 2 a.m. and aside from that, she was dreading having to talk to Martha and Alexis.

She felt a surge of desperate emotion at the thought, the reminder of what she had to tell them, and she hesitated before she pushed the door open. Then again, she reminded herself, they were most likely in their bedrooms at this hour.

Only to falter and stop short a few steps inside as she saw Alexis curled up on the couch, sleeping.

She studied Alexis, thinking absently that she should get a blanket to cover Alexis up with and noting with a swell of sympathy the evidence of dried tears on Alexis's face and the fact that the girl was clutching the very tattered doll, Monkey Bunkey, for comfort. She looked very young and Kate was reminded that Alexis was, for all her maturity, only 19. Kate suddenly drew in her breath, stricken as she realized that Alexis was the same age she herself had been when her mom had died. And if Castle d—Kate cut off the thought furiously. No, he couldn't be. He wasn't! She wouldn't think like that! Couldn't think like that! They would find him! They had to find him!

If they didn't… If they never found out anything concrete… Kate shuddered, mentally recoiling from the thought, the bleak vision of the future. Losing her mother had been devastating, but it had been a clean wound, one that had, eventually, healed, even if the scar from it would always remain. This would be different, this would be worse. This wound would be poisonous, would be kept open and bleeding by virtue of the agonizing hope that came of not knowing for certain what had happened. This wound would never heal. She knew, with awful certainty, that if they never discovered what had happened to Castle, neither she nor Alexis nor Martha would ever get over it.

She pushed the thought away, slamming a mental door on it, her worst fears. She couldn't think about it, couldn't dwell on it. They would find him.

She knelt down in front of Alexis, hesitated, momentarily debating, but then decided she couldn't leave Alexis there. The position didn't look very comfortable.

She put a gentle hand on Alexis's shoulder. "Alexis, sweetie, wake up."

The girl stirred a little. "Daddy?" she mumbled.

Kate flinched. "No, Alexis, it's Kate."

Alexis blinked her eyes open and then sat up abruptly as full consciousness returned. "Is there any news?" she demanded.

"No," Kate answered as gently as she could. "But I do need to tell you and your grandmother something."

Stark apprehension flashed across Alexis's pale face. "Gram's sleeping."

Kate nodded. "I'll tell her in the morning." And she was dreading that conversation only marginally less than she was dreading this one. It hurt to look at Martha now, to see how the always-vibrant woman seemed to have aged years overnight, her spirit dimmed, even as Kate marveled at Martha's strength. Kate hadn't seen Martha actually cry even once, although she knew Martha cried when she was safely out of sight in her bedroom or the bathroom, and Martha steadfastly persisted in talking hopefully, optimistically, about "when Richard returned" until there were times Kate thought her heart might actually be cracking in her chest.

Kate moved to sit beside Alexis on the couch, taking one of Alexis's cold hands in her own. "Alexis, Agent Connors told me today that the FBI is going to… scale back on their search." She didn't—couldn't—tell Alexis that the FBI was not so much scaling back as ending the search.

"But they can't! They have to keep looking! They can't just give up!" Alexis burst out.

Kate steeled herself. Damn, she should have known Alexis was too smart not to read between the lines of what she'd said. God, she didn't know how to do this, didn't know how to do any of this. And for what must have been the billionth time in the last day alone, let alone in the last week, she thought—irrationally—that she needed Castle to help her get through this. Needed his out-of-the-box creative thinking to come up with alternative ways to get clues with their more conventional methods failing and more than that, she needed Castle's humor and his compassion and his understanding to give her the strength to get through this. "Agent Connors explained that after more than a week and without any ransom demand or any new evidence coming to light… well, the FBI doesn't have the resources to keep up with a full-scale search. There are other missing persons they need to investigate."

She inwardly flinched—again—at the memory of Agent Connors telling her that at this point, it was his professional opinion that Castle was missing because he didn't want to be found. Where she'd found the will to resist exploding at Agent Connors for saying it—for giving voice to the usually faint little nagging voice in her head that seemed to get more insistent with every hour that passed with no new leads, with every time she stared at the picture of Castle dropping off that money—she didn't know, but resist she had.

"They can't give up," Alexis said again but this time, her voice was pitifully soft, broken, as she looked at the equipment the FBI had set up in case of a ransom request. The equipment that would be summarily removed in the next few days.

Castle! Castle, where are you? The desperate question echoed through her mind, as it almost constantly did these days, providing a dreary sort of background noise to her increasingly frantic search for any new evidence of where he might be, what might have happened to him.

"Kate," Alexis broke the silence with sudden, startling urgency in her voice.

Kate's gaze snapped up to meet Alexis's painfully familiar blue eyes. "Yes, Alexis?"

"You won't stop looking, will you? You won't give up? You'll keep trying to find him, won't you, Kate? You have to keep looking!"

"I won't stop looking," Kate answered immediately and sincerely.

"You promise?"

Kate nodded, tightening her grip on Alexis's hand. "I swear to you, Alexis, I'll never give up. I'll never stop looking for your dad. And neither will Esposito or Ryan," she added.

The girl managed a wan smile that somehow managed to be more painful to see than tears would have been. "Thanks, Kate. You can't give up. Dad wouldn't—he wouldn't do this. I know he wouldn't. He promised—" her voice faltered but then she swallowed hard and finished, "he promised me once that he would never leave me. He promised and he pinky-swore it too."

Oh God. Kate wondered desperately if there was a limit to how many times her heart could break in a day, even as she tried to smile a little through the tears in her eyes. "He pinky-swore?"

Alexis nodded, her voice unsteady even as she bravely went on, "It was… it was when I was little, when my mom moved out to California after the divorce. I… I cried so much and I… I asked my dad if he would leave me too like my mom had and he got down on his knees in front of me and he promised that he would never ever leave me…" Alexis's voice cracked, the tears welling in her eyes spilling over. "So I know he… he didn't plan this. I don't care what the FBI thinks. They're wrong; they don't know him like… like we do. He didn't leave us."

A sob escaped Kate before she could choke it back and she forcibly swallowed back another sob as she hastily swiped the tears out of her eyes.

Alexis wiped at her own wet cheeks. "Kate, you—you know Dad wouldn't have just left us, right?"

"Yeah, Alexis, I know."

"Dad loved y—" Alexis broke off abruptly, looking even more stricken than she already had, "Dad loves you," she corrected quickly.

Kate's lips trembled into a small smile, the expression feeling unfamiliar on her features after these endless days of grief and worry. "I know. I love him too."

The girl tried but failed to smile and then abruptly pitched over to throw her arms around Kate in a hard hug. Kate closed her eyes as she returned the hug, feeling a surge of love for the girl, for Castle's daughter.

"I miss Dad." Alexis's voice was slightly muffled by Kate's shoulder.

"I miss him too."

"Kate?" Alexis drew back slightly to look at her.

"Hmm?"

"I—I'm really glad you and my dad are getting m— I'm glad my dad has you to look after him."

"Oh, Alexis…" Kate shifted, keeping her arm around Alexis's shoulders as Alexis leaned against Kate and Kate rested her head against Alexis's hair. "Thank you. That means a lot to me." It did. It meant more to her than she could say, was probably the first time in more than a week that she felt something like happiness break through her fog of worry and fear and grief.

"I… I asked my dad to stop working with… the police," Alexis admitted quietly. Kate heard the slight pause, knew Alexis had meant to say that she'd asked Castle to stop working with her.

"When was this?" she asked in as mild and as reassuring of a voice she could muster.

"A couple years ago. When he went back to the precinct in the fall after—after Captain Montgomery's funeral."

After you got shot. The words were left unsaid but Kate heard them anyway, something inside her body flinching at the automatic sensory memory that accompanied the thought.

"It scared me," the girl went on softly. "I—I'd never seen anyone get…"

"You'd never seen a shooting before," Kate finished gently after Alexis's voice broke off in obvious uncertainty.

"Right," Alexis confirmed with a thread of gratitude in her voice. "And to see it when my dad was standing right there… it scared me. I—I knew my dad was getting into more… trouble, but I'd never really seen it. So I asked him to stop. I told him he should stop pretending to be a cop," she finished very quietly in something of a rush, the words almost blurring together as if she were ashamed to be confessing it.

"It's all right, Alexis. I understand."

"But he said he couldn't, because of you, because he owed it to you."

Kate shut her eyes for a moment against the sudden sting of tears, the surge of guilt and regret. Oh, Castle… She wished, more earnestly than ever before, that it hadn't taken her so long, that she'd never felt the need to lie to Castle about not remembering his words in the cemetery that day. If she had only had the courage to tell him she loved him sooner… they could have had so much more time together… They would probably have been married by now, she thought with bitter regret. They could have been already married…

"I knew Dad cared about you before then, that he wasn't just shadowing you for his books anymore, but that was when I realized—when I really knew that he loved you. He'd—he'd never really done that before," Alexis said softly, somehow managing to sound both younger and older than her years. "Until then, he'd never put someone else, what anyone else needed, what he owed to anyone else, before me, before anything I really wanted."

There wasn't even a particle of accusation or hurt in the girl's voice but even so, Kate rushed to reassure her. "Alexis… you know you're still the most important person in your dad's life… Even if I tried, even if I wanted to—which I don't, which I would never do—I couldn't come between you and your dad."

"I know that, Kate," Alexis said with reassuring swiftness and certainty. "I've always known it. And I don't—I'm glad you and my dad are… partners, that you're together. Really."

Kate swallowed back the lump of emotion in her throat. She had wondered if Alexis blamed her for all the dangerous situations Castle had been in because of their partnership. She would entirely understand if Alexis did—for that matter, Kate blamed herself too sometimes, although she tried not to dwell on it and told herself that whatever else, Castle was an adult and responsible for his own choices, but it didn't entirely help. And now, especially, she knew that if she found out that one of the criminals they had put away had done this to Castle, had chosen this means of striking back at them, at her, she would never forgive herself.

"Thank you, Alexis," was all she could say.

"You make him happy," Alexis said softly and simply.

He makes me happy too. The words stuck in her throat and she swallowed hard to try to keep back the sobs. Because he had made her so happy, happier than she had ever been in her life, and she was terrified that she would never see him again. Terrified that she would never feel his arms around her again, never kiss him again, never see his eyes light up with childish glee or soften with tenderness when he looked at Alexis or at her.

And yes, a tiny part of her was terrified that they would find out that somehow Castle had walked away from her—old, old insecurities and fears rising up to take possession of her in her darkest moments because so many people had disappointed her, disillusioned her, betrayed her, left her…

"You make him so happy." Alexis let out a small sob. "He's been so happy. It's how I know he'd never willingly leave you, leave us, leave me." Alexis's voice had been getting progressively softer, more pained with every word, as she seemed to shrink into herself, curling up in an automatic, instinctive defensive position.

She tightened her arm around Alexis's shoulders, more moved than she knew how to express. Alexis was comforting her, she realized, as much as she had thought to comfort Alexis. He's been so happy, Alexis had said… Kate remembered again the sound of his voice in that last phone call, the last time they had spoken. He had been so happy, so confidently joyful. And she knew with a certainty that didn't allow for any doubts or any fears that Castle, the Castle she knew so well, who had sounded so happy in that phone call—that man could not have, would not have willingly left her.

She suddenly found herself remembering the time Castle had been so freaked out by the supposed curse of the mummy, the way he had asked her to look after Alexis if anything happened to him. And now, something really had happened to him and it was up to her right now—while Castle was… gone—to look after Alexis and help Martha. It was another thing she had to do for him, along with not giving up and keeping up the search—she knew that, knew that wherever he was, whatever had happened to him, he would want Alexis to be looked after. Would be more worried for Alexis's sake than he would be for his own.

And Alexis needed it. As mature and as grown-up as she was, Alexis needed looking after. Kate remembered with painful clarity how much she herself had still needed her parents, how much she'd still needed her mother when she had been 19.

She opened her lips to promise Alexis that she would find Castle, that he would be fine—but then swallowed the words. She couldn't make that promise. It killed her that she couldn't make that promise, just as she hadn't been able to make that promise when Alexis had been the one kidnapped. "I won't give up, Alexis. I'll never stop looking," she promised again because it was all she could do, the only promise she could give and knew she would be able to keep.

Alexis sucked in a deep breath. "I know you won't," she said bravely. "And wherever he is, I know Dad knows it too."

Kate tried for a reassuring smile but was afraid it came out looking more like a grimace. "I'm sure he does know it." She stood up. "It's late, Alexis. You should try to get some sleep."

The girl nodded, clutching Monkey Bunkey to herself as if it were a talisman of sorts promising her father's safe return. "Night, Kate. And thanks."

"I'll see you in the morning, Alexis."

Kate watched Alexis go up the stairs and then sighed, having to make an effort to move her feet that suddenly felt as heavy as concrete blocks, to turn off the lights and make her own way through Castle's study and into their bedroom.

The sheer size of the bed seemed to slap her in the face, as it had every day of the last week, the reminder that he wasn't there to share it. Kate felt despair threatening—again—and she reached over to pick up the picture on his nightstand, one of the two of them taken at his surprise birthday party after the elaborate fake murder she'd staged. In it, she had just laughed at something Martha had said and the camera had caught Castle smiling as he watched her interact with his mother.

She touched a finger to Castle's smiling face in the picture and suddenly remembered what he'd said to her… just last week, even if it felt like a lifetime ago now. She saw the look on his face, could hear his voice again in her mind as clearly as if he were in the room with her… Maybe it is a sign—a sign that ours is a great love story. What's a great love story without obstacles to overcome? Every fairy tale has them—terrible trials that only the worthy can transcend. But you can't give up. That's the deal. We want the happy ending, we can't give up.

This was that terrible trial.

And she found herself speaking aloud to the picture—to Castle himself, even, wherever he was. "I won't give up, Castle. I promise you, I'll never give up on us, on our love story."

Just stay alive, Castle, she added silently, not able to bring herself to acknowledge aloud that he might not.

Even if it took months or—God forbid—years, she would not give up. She would never give up and she could only hope and pray desperately to the Fates or whatever higher powers might be listening that their "great love story" would have a happy ending.

~The End~